2 3 4 5-triazine 6-tri(2-pyridyl)-1 Co-bpdc Co-bpdc/MWCNTs composites Fe-N-C catalyst Q1-390 QC1-999 active site alkaline bacterial cellulose/poly(methylene blue) hybrids bic Book Industry Communication::G Reference, information & interdisciplinary subjects::GP Research & information: general binary nitrogen precursors cobalt and nitrogen co-doped cobalt-based electrocatalysts electrocatalysis electrocatalyst electrophilic Ni3+ and O? fuel cells g-C3N4 graphene-carbon nanotube aerogel heteroatom doping hydrogen evolution reaction layered double hydroxide manganese dioxide mesoporous NiO metal-free catalysts metal–organic framework